There has been provided an image forming device that can write or read data stored in an IC chip (storage unit) called RFID attached to a recording medium when forming images on the recording medium. Such a conventional image forming device is able to re-convey the recording medium for re-accessing the IC chip even if a try to access the IC chip has once failed. However, even though the recording medium is brought back to re-access the data in the IC chip, if the IC chip stores too much information to be accessed at a time, such a re-try tends to result in another failure.